Chair control for tilting and swivel chairs having improved tensioning bolt



Feb. 13, 1968 F. DOERNER 3,368,844

CHAIR CONTROL FOR TILTING AND SWIVEL CHAIRS HAVING IMPROVED TENSIONING BOLT Filed 001;. 17, 1966 \NVENTOR F ANK 0051mm ATTORNEY United States Patent 3,368,844 CHAIR CONTROL FOR TILTING AND SWIVEL CHAIRS HAVING IMPROVED TENSIONING BOLT Frank Doerner, Waterloo, Ontario, Canada, assignor to Doerner Products Co. Limited, Waterloo, Ontario, Canada, a corporation of Canada Filed Oct. 17, 1966, Ser. No. 587,021 3 Claims. (Cl. 297303) This invention relates to a chair control for tilting and swivel chair and in particular to a novel tension member for tensioning the coil spring employed in this type of chair.

The invention relates to an improvement in the type of chair control disclosed in United States Patent No. 3,278,228, dated Oct. 11, 1966.

It is an object of the present invention to simplify the construction of that type of chair control so as to obtain economies in the manufacture and assembly as well as improving the sturdiness of the structure and its compactness.

Other and further advantages of the present invention wil be apparent from the following description which is illustrated by the accompany-ing drawings in which:

FIGURE 1 is a perspective side elevation of a tilter chair embodying the invention which is the subject of the present application with the chair control shown in vertical cross-section.

FIGURE 2 is a fragmentary view of FIGURE 1 showing the chair tilted.

FIGURES 3, 4 and 5 are fragmentary views of the tensioning bolt and associated parts on an enlarged scale to illustrate their construction.

FIGURE 6 is a fragmentary perspective view of a part of the chair control.

The invention will first be described with reference to the embodiment disclosed in the drawings. The chair per se comprises a mobile base 10 which is provided with a conventional support post 11, the chair control device which is generally indicated by the letter A and having a fixed frame, indicated by the letter B, mounted on the top end of the post 11 and a pivotal frame, generally indicated by the letter C, pivotally connected to the fixed frame which pivotal frame is rigidly connected to the underside of the chair seat indicated by the numeral 12. The pivotal frame is yieldably connected to the fixed frame by the components which will hereafter be described in relation to the invention of the present application.

The fixed frame comprises a base plate 13 having a pair of spaced apart upright arms 14, 15 formed integrally therewith to thereby form a substantially U-shaped frame. The base plate supports a U-plate comprising a fiat post holder 16 with downturned edges 17 which are fastened to the base plate 13. The holder 16 is formed with a central opening 18 which registers with an opening 19 in the base plate 13. The upper end of the post 11 is fitted into the openings referred to with a rigid fit so that the fixed frame is rigidly and firmly supported on the top end of the post. To that end, the upper end of the post 11 and the walls defining the openings 17, 18 may be given self-holding tapers. The complete chair assembly can revolve about the vertical axis of the post 11.

The forward portion of the plate 16 is formed by a forwardly opening slot de'fined by a slot 19 and a wider portion 20 with retaining shoulders 21, 22. The purpose of the slot will be described later.

The second frame member comprises a substantially U-shaped strap having a vertical pressure plate 23 and rearwardly extending arms 24 and 25 so dimensioned to receive the arms 14, 15 of the fixed frame therebetween with the pressure plate 23 in a plane perpendicular to the base plate 13. The second frame is pivotally connected by means of the pivot rod 26 to the arms 14, 1-5 with the lower edge of the pressure plate 23 resting against the base plate '13 to provide a stop position for the usual purpose. The pivot 26 is located to permit movement of the second frame away from the stop position. The second frame which comprises the pressure plate 23 and the arms 24 and 215 is connected to the chair seat 12 through the medium of the attaching bracket or spider 27 to which the arms 24 and 25 respectively are attached. The pressure plate is formed with a substantially large opening 28 therethrough with an annular depression 28' bordering said opening.

The biasing means for yieldably interconnecting the fixed frame and the second frame, comprises the following components namely a tie-rod 29 which is entered through the opening 28 formed in the pressure plate 23 with its enlarged head 30 engaged against the shoulders 21, 22 (see FIG. 5); a compression spring 31 mounted on the tie-rod 29 and having one end seated in the annular depression 28 and its other end seated against a collar 32 which is held in place by a conventional adjusting handle 36, the spring thus being captured between the pressure plate 23 and the collar 32. The face of the head 30 which engages the shoulders 21, 22 is a concave bearing surface as indicated at 34. This permits a rocking movement between the bearing surface and the shoulders with substantially no wear.

The assembly and dismantling of the biasing means is quite simple and substantially self-explanatory from the drawings. FIGURE 1 illustrates the chair control completely assembled. The head 26 is inserted in portion 20 with the concave bearing surface 34 resting against shoulders 21, 22. The compression spring 31 is placed in osition and the collar 32 and adjusting handle 33 mounted as shown.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. In a chair control for a tilting chair having a base, a chair support member, a fixed frame carried by the member, a second frame pivotally mounted on the fixed frame for limited pivotal movement about a horizontal axis relative to the fixed frame, said second frame having means for attaching it to a chair seat, and biasing means yieldably connecting the fixed frame and the second frame and urging said second frame to a stop position relative to the fixed frame and yieldably resisting pivotal movement of the second frame away from said stop position under a force applied by an occupant of the chair, said biasing means comprising (a) a substantially rigid connect-ing member disposed in a horizontal plane transverse to said horizontal axis,

(b) said connecting member having at one end an integrally formed head seated in an open slot formed in said fixed member, said slot having retaining shoulders,

(c) a fixed pressure plate secured to the second frame and having an opening through which said connecting member extends,

(d) a spring surrounding said connecting member having one end seated on the pressure plate and the other end restrained by a tension adjusting wheel mounted on the other end of the connecting member.

2. In a chair control according to claim 1 in which said head has an arcuately formed bearing surface seating on said retaining shoulders.

3. In a chair control according to claim 1 in which said head has a concave bearing surface seating on said 2,818,911 retaining shoulders. 2,845,992 3,185,429 References Cited 3,278,228 UNITED STATES PATENTS 5 3,290,091

1,836,630 12/1931 Thum 297-303 2,424,753 7/1947 Herold 297303 XR 2,528,223 10/1950 Fox 297-301 4 Syak 297303 XR Cramer 297-303 Meinhardt 297303 XR Doerner 297-303 Goodman 297302 BOBBY R. GAY, Primal Examiner.

G. O. FINCH, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,368 ,844 February 13, 1968 Frank Doerner It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 59, "member" should read frame Signed and sealed this 11th day of November 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

1. IN A CHAIR CONTROL FOR A TILTING CHAIR HAVING A BASE, A CHAIR SUPPORT MEMBER, A FIXED FRAME CARRIED BY THE MEMBER, A SECOND FRAME PIVOTALLY MOUNTED ON THE FIXED FRAME FOR LIMITED PIVOTAL MOVEMENT ABOUT A HORIZONTAL AXIS RELATIVE TO THE FIXED FRAME, SAID SECOND FRAME HAVING MEANS FOR ATTACHING IT TO A CHAIR SEAT, AND BIASING MEANS YIELDABLY CONNECTING THE FIXED FRAME AND THE SECOND FRAME AND URGING SAID SECOND FRAME TO A STOP POSITION RELATIVE TO THE FIXED FRAME AND YIELDABLY RESISTING PIVOTAL MOVEMENT OF THE SECOND FRAME AWAY FROM SAID STOP POSTION UNDER A FORCE APPLIED BY AN OCCUPANT OF THE CHAIR, SAID BIASING MEANS COMPRISING (A) A SUBSTANTIALLY RIGID CONNECTING MEMBER DISPOSED IN A HORIZONTAL PLANE TRANSVERSE TO SAID HORIZONTAL AXIS, (B) SAID CONNECTING MEMBER HAVING AT ONE END AN INTEGRALLY FORMED HEAD SEATED IN AN OPEN SLOT FORMED IN SAID FIXED MEMBER, SAID SLOT HAVING RETAINING SHOULDERS, (C) A FIXED PRESSURE PLATE SECURED TO THE SECOND FRAME AND HAVING AN OPENING THROUGH WHICH SAID CONNECTING MEMBER EXTENDS, (D) A SPRING SURROUNDING SAID CONNECTING MEMBER HAVING ONE END SEATED ON THE PRESSURE PLATE AND THE OTHER END RESTRAINED BY A TENSION ADJUSTING WHEEL MOUNTED ON THE OTHER END OF THE CONNECTING MEMBER. 